Researchers Discover a ‘Teen’ Gene

As often confirmed in the stories of parents of adults with mental disorders, the first symptoms of a "behavior a bit odd" appear in the teenage years. We now know that during this phase of brain development, adolescents are particularly vulnerable to psychiatric disorders, including schizophrenia, depression and addiction.

Researchers at the Douglas Institute Research Center, affiliated with McGill University, have isolated a gene, DCC, which is responsible for dopamine connection in the medial prefrontal cortex during adolescence. Working with mice that had altered expression levels of DCC, the researchers established that dysfunction of this gene during adolescence leads to behavioral consequences in adulthood.

This breakthrough provides the first clues that could lead to a better understanding of this crucial period of brain development. Some problems may be related to alterations in the functioning of the prefrontal cortex and changes the activity of dopamine, a brain chemical. The circuitry of the prefrontal cortex continues to develop until early adulthood, through mechanisms that are, so far, completely unknown.

The researchers hope that this discovery may open new avenues for prevention and treatment. In psychiatric settings, there is a consensus that therapy and support early adolescence, at the onset of a first mental health problem, offer significantly better prospects for favorable treatment outcomes and better health during adulthood.

Even subtle variations of DCC during adolescence produce significant changes in the functioning of the prefrontal cortex in later life. To determine whether the findings of this basic research are transferable to humans, the researchers examined the expression of DCC in the brains of people who committed suicide. Surprisingly, these brain showed higher expression levels of DCC, some even 48 percent higher than those of control subjects.

The prefrontal cortex is associated with judgment

"The prefrontal cortex is associated with judgment, decision making and cognitive flexibility; the ability to change plans in front of an obstacle," said Cecilia Flores, associate professor, Department of Psychiatry McGill University and lead author of the research. "Operation is important for learning, motivation and cognitive processes. Because the prefrontal cortex develops over a long period of time that extends into adulthood, this region is particularly malleable to life experiences in adolescence, such as stress and addictions. These changes in the development of the prefrontal cortex may cause long-term consequences later in life. "

Hope to reverse the course of disease

Identification of the first molecule involved in the mode of maturation of the prefrontal dopaminergic system now gives researchers in psychiatry a target for further research and, ultimately, to develop pharmacological therapies and other treatments. "We know that the DCC gene may be modified by the experiences of adolescence," said Flores. "That gives us a hope that therapy, including social support, may alter the functioning of the DCC gene during this critical phase and, perhaps, reduce vulnerability to [mental health] diseases."